Phytochemical profile, antioxidant, and antimicrobial activities of

Tinospora crispa L. (brotowali) is a traditional medicinal plant used in Southeast Asia to treat fever, diabetes, and infections. This study evaluated the phytochemical composition, antioxidant potential, and antimicrobial activity of its stem fractions. Dried stems of simplicia were extracted with 70% ethanol and fractionated into n-hexane, chloroform, ethyl acetate, and aqueous fractions. Phytochemical screening, total flavonoid, phenolic, and tannin content determination, DPPH radical scavenging assay, antibacterial testing, and Liquid Chromatography–Mass Spectrometry (LC–MS) profiling were performed. The ethyl acetate fraction exhibited the strongest antioxidant activity (IC₅₀ = 24.47 µg/mL), correlating with its highest flavonoid (89.76 mg QE/g), phenolic (41.14 mg GAE/g), and tannin (114.17 mg TAE/g) levels. LC–MS analysis tentatively identified 28 compounds, with siomenine as the major alkaloid. Antibacterial evaluation revealed moderate inhibition zones (4–11 mm) against Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. However, all tested microorganisms were classified as resistant according to Clinical and Laboratory Standards Institute (CLSI) criteria. Overall, this study demonstrates that polarity-guided fractionation effectively enriches antioxidant constituents in T. crispa L. stems. Further optimization, including MIC/MBC determination and advanced structural confirmation, is required to enhance antibacterial efficacy and substantiate its potential for pharmaceutical or functional applications.